Expandable arbor assembly

ABSTRACT

An expandable arbor for supporting abrasive coated sleeves. The arbor has an exterior slotted shell which is expanded by expander elements located in the shell and supported on an axially extending shaft. The expander elements have outwardly movable fingers formed around the peripheries thereof and which engage the shell to expand the shell into contact with the abrasive coated sleeves. The fingers are expanded by threaded members having inclined conical head surfaces which engage complementary surfaces of the expander element fingers. Aligned passages are provided in the expander elements and the supports to permit access to the expander elements from the ends of the shell.

United States Patent Harz Mar. l4, 1972 [s41 EXPANDABLE ARBOR ASSEMBLY 2,616,462 11/1952 Haddican ..269/48.l x [72] Inventor: Edward F. Harz, Geneva, Ill. FOREIGN PATENTS 0R APPLICATIONS 1 1 Assignee: fi Industries lnwrmmed, Chicago, 226,759 10/1910 Germany ..sum 2 Z N 7 Primary Examiner-Donald G. Kelly I 2] ed 1970 Attorney-Walter L. Schlegel,Jr. and John w. Yakimow [21] Appl. No.: 88,828

[57] ABSTRACT [52] US. Cl ..279/2, 51/372, 269/48.1 An expandable arbor for supporting abrasive coated sleeves. [51] Int. Cl ..B24d 9/02 Th arbor has an exterior slotted shell which is expanded by [58] Field at Search ..51/372, 373; 279/2; 269/48.1 p n r elements located in the h l n upp r e on an axially extending shaft. The expander elements have out- [5 R f r Cited wardly movable fingers formed around the peripheries thereof and which engage the shell to expand the shell into contact UNITED STATES PATENTS with the abrasive coated sleeves. The fingers are expanded by threaded members having inclined conical head surfaces 2 g g complementary Surfaces of the expander 2'767'677 56 r "51/372 ment fingers. Aligned passages are provided in the expander l 9 Jo "369/481 elements and the supports to permit access to the expander i g gfg :2 elements from the ends of the shell.

r0 1 an Re. 25,976 11/1961 Toulmin ..51l372 X 16 Claims, 9 Drawing Figures Patented March 14, 1972 2 Sheets-Sheet l [A M/00F. m {Q5 2: fi! fine 5 Patented March 14, 1972 2 Sheets-Sheet 2 EXPANDABLE ARBOR ASSEMBLY SUMMARY OF THE INVENTION This invention is concerned with an expandable arbor and more particularly with an expandable arbor for supporting abrasive coated sleeves to form an abrasive planing drum.

An object of this invention is an abrasive planing drum comprising a number of abrasive coated sleeves which may easily be mounted on and removed from an expandable arbor.

Another object is an abrasive drum having an expandable arbor which can be expanded and contracted from the ends thereof.

Another object is an abrasive drum having a number of individual abrasive coated sleeves each of which is individually locked to an expandable arbor.

Another object is an expandable arbor which is lightweight yet rigid.

Another object is an expandable arbor having a nontapered shell.

Another object is an expandable arbor which provides intermediate supports for the sleeves supported thereon.

Another object is an expandable arbor which may be used as part of a drive roller.

Another object is an expandable arbor which may be used as part of a printing roller.

Other objects may be found in the following specification, claims and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated more or less diagrammatically in the following drawings wherein:

FIG. 1 is a side elevational view of an abrasive planing drum embodying the novel features of this invention;

FIG. 2 is a side elevational view of the expandable arbor used in the abrasive planing drum of FIG. 1;

FIG. 3 is a longitudinal cross-sectional view of the expandable arbor taken along line 3-3 of FIG. 2;

FIG. 4 is an end view of the abrasive planing drum taken along line 44 of FIG. 3;

FIG. 5 is a cross-sectional view of the abrasive planing drum DESCRIPTION OF THE PREFERRED EMBODIMENTS An abrasive planing drum embodying the novel features of this invention is shown in FIG. 1. The drum includes a number of abrasive coated sleeves 17, in this case five, supported on an expandable arbor 19. The abrasive coated sleeves 17 are formed of metal coated with an abrasive such as tungsten carbide grits by brazing or other means.

The expandable arbor 19, which is shown in plan in FIG. 2 and in cross section in FIG. 3, includes an outer tubular shell 21 having longitudinally extending slots 23 which is mounted and supported on annular supports 27. The slots 23 are circumferentially spaced around the shell and are interrupted or noncontinuous for the length of the shell. The annular supports are welded to a shaft 29 at spaced positions along the length thereof with the welds indicated by the numerals 31.

Expander elements 37 are mounted on the shaft 29 with each expander element positioned adjacent a support. Each expander element is located on the side of its support which is closer to an end of the shell 21. The expander elements are fastened to the tubular shell 21 by means of welds 39 shown most clearly in FIGS. 6 and 7. The welds are made in circumferentially extending slots 41 formed in the tubular shell 21. It

should be noted that the circumferentially extending slots 41 are centered between the longitudinally extending slots 23.

The annular supports 27, shown in detail in FIG. 5, have a number of passages formed therein and positioned in a circle. The passages are arranged in groups of three with two passages 45 of each group having smooth circular cross section and a third passage 47 of circular cross section having a smaller diameter which is threaded. In this embodiment, and for reasons to be explained later, there are four groups of passages in each support with each passage spaced thirty degrees from each adjacent passage.

The expander elements 37, shown in detail in FIGS. 4, 6, and 8, are formed with expanding fingers 51 located about the periphery thereof. The fingers are each defined by the outer periphery of the expandable element and by a slot 53 which extends along a chord of the expander element from the periphery thereof at one end of the slot to short of the periphery of the element at the opposite end of the slot. In this embodiment, four slots 53 are formed in the element to form four expanding fingers 51. As can best be seen in FIGS. 4 and 6, the free ends of the fingers face in the same direction of rotation.

Three passages are formed in each expander element for each finger thereof and are spaced along the length of each slot 53. The passages 55 which are located at the closed end of each slot and adjacent the outlet of the slot are circular in cross section and are of uniform diameter. The passage 57 which is located along each slot between the passages 55 is formed with somewhat conical walls 59, as shown in FIGS. 7 and 8. As is best shown in FIG. 7, the threaded passages 47 of each support plate 27 are aligned with the passages 57 of their respective expander members.

Hexagonal socket head screws 67 having threaded portions 69 which engage the threaded passages 47 in the support plates 27 and headed portions 71 of conical shape which engage the conical walls 59 of the expander elements 37 are provided for actuating the fingers 51 of the expanded elements 37. The screws 67 are rotated by an elongated hex head wrench.

As can be most clearly seen in FIG. 3, there are three sets of annular supports and expander members on each side of a transverse center line through the expandable arbor-l9. Also, on each side of the center line, each expander element 37 is located on the side of its respective support member 27 which faces the closest end of the shell 21. Further, the hexagonal sockets on the screws 67 face towards the nearer end of the shell. To enable the sockets of the screws to be reached from the ends of the shell, the screws 67 on the expander plates 37 located inside of the expander plates located at each end of the shell align with passages 45 and 55 in the support members and expander plates located outwardly of them. This is accomplished by progressively positioning each expander plate and its associated support member 30 out of phase relative to the next adjacent outwardly located set of expander members and support members on the same side on the center line of the arbor.

The modified form of the invention shown in FIG. 9 utilizes an adhesive 81 between the arbor shell 21 and the abrasive coated sleeves 17.

The use, operation and function of the invention are as follows:

, The abrasive planing drum 15 of this invention is constructed so as to enable a user to readily install and remove the abrasive coated sleeves 17 through use of an elongated hexagonal socket head screw tool. To remove a sleeve 17, the hexagonal socket head screw tool is inserted in the appropriate end of the shell 21 through the sets of passages 55 in the expander elements 37. The tool will then also extend through aligned passages 45 in the support plates 27 The expander screws of the innermost expander element may be reached through one set of aligned passages of each finger.

The expander screws of the intermediate expander element is reached through the other set of aligned passages of each finger. The expander screws of the outermost expander element, of course, are readily accessible from the end of the arbor as can be seen in FIG. 4. All of the expander screws may be loosened in this manner. With the screws loosened, the fingers 51 will return to their unextended positions, allowing the tubular shell 21 to retract to its undistorted diameter, and permitting removal of the abrasive coated sleeves 17. The new sleeves may be installed in the reverse manner.

When one of the expander screws 67 is inserted into a threaded passage 47 in a support member27, its conical head 71 will engage the conical walls 59 of the passage 57 in the expander element 37. As the screw is threaded into the support member, the finger 51 will be forced radially outwardly and will expand the arbor shell 21 to the position shown by dashed lines in FIG. 8. The expansion of the arbor shell 21 will lock the abrasive sleeves l7 thereto. It should be noted that the expander screws engage the fingers at about the middle thereof.

To avoid projections or bumps in the abrasive sleeves 17, it is important that the longitudinal slots 23 of the shell 21 do not align with the open ends of the slots 53 which form the expanding fingers. However, in order to obtain maximum expansion of the arbor shell, it is desirable that the longitudinal slots 23 be located reasonably close to the ends of the expanding fingers 51 somewhat in the manner shown in FIGS. 6 and 8. It should be observed in FIG. 2 that the slots 23 in the shell are not continuous and are spaced around the periphery of the shell both circumferentially and longitudinally so that a longitudinal slot is provided near the free end of each expander finger 51. The flexibility of the arbor shell 21 is also improved by locating the welds 39 which connect the expander elements 37 to the arbor shell near the base of each expandable finger in the manner shown in FIG. 6.

Although, this embodiment of the invention is shown with four expanding fingers 51 on each expander element 37 and with five abrasive sleeves per drum it should be understood that other combinations of fingers and sleeves may be used with suitable modifications. For example, the number of sets of support members 27 and expander elements 37 required are equal to the number of abrasive sleeves plus one which are positioned on the arbor. The number of expanding fingers provided is not critical as long as they are uniformly spaced around the periphery of the expander element.

The number of aligned access passages 45 and 55 required in the support members and expansion members are equal to the number of expansion members accessible from each end of the arbor shell minus one. Using these relationships, the number of expander elements, the number of expander fingers, and the number of abrasive sleeves used on the arbor may be varied.

The use of a nontapered expandable arbor 19 provides a tighter fit for the abrasive coated sleeves 17. To avoid out-ofround problems with the abrasive coated sleeves, it has been found desirable to provide an interference fit between the sleeves and the unexpanded arbor. With such a fit, the amount of expansion of the expander elements required to hold the sleeves in place is reduced to a minimum.

This invention generally eliminates the need for adhesives for attaching the abrasive coated sleeves to the arbor. However, this expandable arbor may also be used in combination with an adhesive, as shown in FIG. 9, to hold the sleeves in position on the arbor.

The expandable arbor of this invention may also be used in other environments. A drive roller and a printing roller are examples of possible uses of the expandable arbor. Therefore, the scope of this invention should not be to the embodiments shown and described herein, but should be determined by the claims attached hereto.

I claim:

I. An expandable arbor including:

a shaft,

a plurality of supports spaced apart along the length of said shaft and affixed thereto,

a plurality of expander elements mounted on said shaft, a tubular shell mounted on said support and extending over said expander elements,

a plurality of circumferentially spaced, longitudinally extending, noncontinuous slots formed in said tubular shell, and

means accessible from the ends of said shell for expanding said expander elements to expand said shell and to allow said expander elements and said shell to return to their unexpanded conditions.

2. The arbor of claim 1 further characterized in that said expander elements are each formed in the shape of an annular disk, each expander disk is attached at a plurality of locations to said shell, and each expander disk has a plurality of outwardly moveable fingers formed about the periphery thereof.

3. The arbor of claim 2 further characterized in that said expander fingers are formed by chordally extending slots formed in said expander disks and said disks are fastened to said shell adjacent the bases of said fingers.

4. The arbor of claim 2 further characterized in that said means for expanding said expander elements engage said fingers to force said fingers radially outwardly to expand said shell.

5. The arbor of claim 3 further characterized in that a passage is formed in each of said slots in at least one location with said passage formed and adapted to receive said means for expanding said expander elements.

6. The arbor of claim 5 further characterized in that said passage is formed with a cam follower surface.

7. The arbor of claim 6 further characterized in that said means for expanding said expander elements includes a member having a cam surface engageable with said cam follower surfaces of said passage.

8. The arbor of claim 5 further characterized in that in each of said slots at least one access passage is formed with said access passage fonned and adapted to permit passage of means to engage and manipulate said means for expanding said expander fingers.

9. The arbor of claim 5 further characterized in that in each of said slots at least one access passage is formed with the number of access passages equal to the number of expander elements less one which are accessible from one end of said shell.

10. The arbor of claim 9 further characterized in that said means for expanding said expander elements which are accessible from one end of said shell and located inwardly of the first expander element at the end of the shell are aligned with said access passages in the other elements located between said means and the end of the shell.

11. The arbor of claim 10 further characterized in that the expander means receiving passage of each expander element slot is located approximately in the midpoint of said slot and between the access passages of said slot if more than one access passage is provided.

12. The arbor of claim 8 further characterized in that passages are provided in said supports to permit access to the expander means of said expander elements.

13. The arbor of claim 5 further characterized in that said support means are formed with threaded passages, said means for expanding said expander elements includes a member having a threaded portion and a cam portion, said threaded portion adapted to engage said threaded passage of said support and said cam surface adapted to engage said cam follower surfaces of said passage.

14. The arbor of claim 13 further characterized in that a support is positioned adjacent to each expander element.

15. The arbor of claim 2 further characterized in that four fingers are provided in each expander disk.

16. The arbor of claim 2 further characterized in that the free end of each finger is positioned adjacent a longitudinal slot in said shell. 

1. An expandable arbor including: a shaft, a plurality of supports spaced apart along the length of said shaft and affixed thereto, a plurality of expander elements mounted on said shaft, a tubular shell mounted on said support and extending over said expander elements, a plurality of circumferentially spaced, longitudinally extending, noncontinuous slots formed in said tubular shell, and means accessible from the ends of said shell for expanding said expander elements to expand said shell and to allow said expander elements and said shell to return to their unexpanded conditions.
 2. The arbor of claim 1 further characterized in that said expander elements are each formed in the shape of an annular disk, each expander disk is attached at a plurality of locations to said shell, and each expander disk has a plurality of outwardly moveable fingers formed about the periphery thereof.
 3. The arbor of claim 2 further characterized in that said expander fingers are formed by chordally extending slots formed in said expander disks and said disks are fastened to said shell adjacent the bases of said fingers.
 4. The arbor of claim 2 further characterized in that said means for expanding said expander elements engage said fingers to force said fingers radially outwardly to expand said shell.
 5. The arbor of claim 3 further characterized in that a passage is formed in each of said slots in at least one location with said passage formed and adapted to receive said means for expanding said expander elements.
 6. The arbor of claim 5 further characterized in that said passage is formed with a cam follower surface.
 7. The arbor of claim 6 further characterized in that said means for expanding said expander elements includes a member having a cam surface engageable with said cam follower surfaces of said passage.
 8. The arbor of claim 5 further characterized in that in each of said slots at least one access passage is formed with said access passage formed and adapted to permit passage of means to engage and manipulate said means for expanding said expander fingers.
 9. The arbor of claim 5 further characterized in that in each of said slots at least one access passage is formed with the number of access passages equal to the number of expander elements less one which are accessible from one end of said shell.
 10. The arbor of claim 9 further characterized in that said means for expanding said expander elements which are accessible from one end of said shell and located inwardly of the first expander element at the end of the shell are aligned with said access passages in the other elements located between said means and the end of the shell.
 11. The arbor of claim 10 further characterized in that the expander means receiving passage of each expander element slot is located approximately in the midpoint of said slot and between the access passages of said slot if more than one access passage is provided.
 12. The arbor of claiM 8 further characterized in that passages are provided in said supports to permit access to the expander means of said expander elements.
 13. The arbor of claim 5 further characterized in that said support means are formed with threaded passages, said means for expanding said expander elements includes a member having a threaded portion and a cam portion, said threaded portion adapted to engage said threaded passage of said support and said cam surface adapted to engage said cam follower surfaces of said passage.
 14. The arbor of claim 13 further characterized in that a support is positioned adjacent to each expander element.
 15. The arbor of claim 2 further characterized in that four fingers are provided in each expander disk.
 16. The arbor of claim 2 further characterized in that the free end of each finger is positioned adjacent a longitudinal slot in said shell. 